Background:zookeeper-server is the main-module of the zk codebase. Unfortunately, there were many checkstyle violations in it. To improve the code quality and code standards, IMHO, it's time to clean up the all the checkstyle violations(turn on the <failOnViolation>true</failOnViolation>). we can learn from the hbase whose checkstyle(almost 40+ rules) is very strict and ensures a very unified code style.(https://github.com/apache/hbase/blob/master/hbase-checkstyle/src/main/resources/hbase/checkstyle.xml) My planing is: clean up the all the checkstyle one rule by another to avoid too much code changes for review. Everything's hard in the beginning, I have fired my first shot(https://github.com/apache/zookeeper/pull/992). If this draft has accepted by the community, I will create the corresponding sub-tasks for more people joining this work.
Cited the comment from Enrico Olivelli in the ZOOKEEPER-3431:--------------------------------------------------------------we have to discuss this topic with the community.I have experience on BookKeeper, we had to clean up groups of packages.This is the kind of stuff that invalidates all of the pending pull requests.I have already sett up a basic checkstyle configuration file and it is already active but it is performing only very basic checks (like no 'author' tags).I will appreciate very much if you want to drive this effort, personally I would start this stuff after 3.6.0 release, once we consolidate current master and the maven build. I would have sent an email on the dev@ list soon.We also have to agree on the checkstyle configuration, it is not trivial, I would take the file from HBase, BookKeeper or other ASF projects on the Haddoop ecosystem.
